The well-known traditional vapor compression refrigeration cycle is considered to be the most effective technique used in the field of refrigeration and air-conditioning systems. It’s used almost in every facility including industrials, homes and food storages. There are some environmental hazards concerning the use of vapor-compression cycles such as global warming and ozone layer depletion mainly due to refrigerant's leakages. However, it's still considered as a leading technology for its capability of producing high cooling and heating powers with great coefficient of performance. The present work represents an experimental investigation of the effect of the condenser's temperature on the thermal performance of a conventional vapor compression refrigeration cycle. The geothermal cooling technique was introduced and utilized for cooling the temperature of the condenser that operates in harsh climate conditions. The experiment was performed using two additional heat exchangers for enabling heat exchange with geothermal temperature. The first heat exchanger (primary HX1) was connected directly to the condenser while the other one (secondary HX2) was installed inside the geothermal hole intended for heat exchange with the geothermal temperature. These exchangers (HX1 and HX2) were thermally connected via two PVC tubes with straight water circulating inside them (using a DC water pump). The experimental results proved the success of the current utilized method in improving the thermal performance of the system. Cooling the condenser via geothermal cooling has led to a considerable reduction in the temperature of the refrigerant and improved the overall performance of the cycle. The experimental apparatus showed an increase in both cooling capacity and COP by 25% and 21.5%, respectively. In addition, a considerable enhancement in the temperature of the evaporator was accomplished to reach a minimum temperature of 14.5ºC.

A conventional vapor compression refrigeration cycle is among the most effective technology in refrigeration systems. In the present experimental study, thermal performance and the effect of the condenser temperature have been analyzed. With the decrease in the condenser temperature, the overall performance of the refrigeration cycle is increased. However, the cooling power and efficiency of conventional vapor pressure air conditioning units can experience a significant reduction when operating in extreme weather (hot and dry). This drop is mainly affected by the increase in the temperature (and pressure) of the condenser with an increase in the ambient air temperature. Unfortunately, Iraq experiences the most extreme summer seasons especially in the months of June and July when the temperature reaches or exceeds 50° C. So, ground cooling has been used in areas with a hot environment for split system air conditioners. Evaporative cooling was also performed to lower the coolant temperature of the AC unit used inside the condenser area. Experimental results showed that when using a geothermal heat exchanger, the temperature of the condenser is reduced from 116 to 110 ° C and the coefficient of performance (COP) is improved by 41%. In addition to this when the system uses evaporative cooling the temperature of the condenser is reduced from 110 ° C to 88° C. Moreover, a 65% improvement was made in the COP of the conventional vapor compression refrigeration cycle. Furthermore, with a decrease in the evaporator temperature from 6 to 3.5 °C there was an increase in refrigeration capacity by an average of 52%.